Anchoring and seal mechanisms for well tools



LAW?

Jan. 26, 1960 Filed Jan. 9, 1958 J. WALL, JR., ETAL 2,922,477

ANCHORING AND SEAL MECHANISMS FOR WELL TOOLS 2 Sheets-Sheet 1 32 -45 Y5" A JAV I 55 VF F wNL/F o 7 "ll 57 l9 f ao E '2 5 I8 7 l2 9 16 j :46 4+4 INVENTOR 29 John Wall, Jr.

- .29 2' William I Mitchell 2'42 4 Fig 0 I ATTORNEY Jan. 26, 1960 J.WALL, JR. ET AL 2,922,477

ANCHORING AND SEAL MECHANISMS FOR WELL TOOLS Filed Jan. 9, 195 8 2Sheets-Sheet 2 United States ANCHORING AND SEAL MECHANISMS FOR WELLTOOLS Application January 9, 1958, Serial No. 708,023

14 Claims. (Cl. 166136) This invention relates to well tools and moreparticularly to an anchoring and sealing mechanism for a well toolpositionable in a desired location in the well for anchoring the Welltool, such as pump seating nipple, in operative position in the well atthe desired location.

One object of the invention is to provide a new and improved anchoringtool which is positionable at a desired location in the tubing string ofa Well.

Still another object is to provide an anchoring tool, of the typedescribed, :which may be lowered to the desired location by use of arunning tool suspended on a flexible line or member and anchored in theWell tubing by jars imparted to the running tool.

A further object is to provide an anchoring tool, of the type described,having positively expansible sealing means for sealing between theanchoring tool and the well tubing when the anchoring tool is locked tothe tubing string at the desired location.

Another object of the invention is to provide an anchoring tool, of thetype described, having a pump seating nipple for receiving and engaginga pump hold down device of a pump assembly.

Still another object is to provide an anchoring tool, of the typedescribed, having a locking means for releasably securing the anchoringtool in the well tubing.

A further object is to provide a well tool having a tubular memberprovided with outwardly movable members for engaging a downwardly facingshoulder of a well tubing for holding the tool in a desired position inthe well tubing and a downwardly movable lock mandrel for maintainingthe outwardly movable members in outer positions whereby the tool isheld against movement in the well tubing when the lock mandrel is in alower position in the tubular mandrel.

A further object is to provide a well tool, of the type described,having latch means for releasably holding the movable members in innerpositions out of engagement with the well tubing while the well tool isbeing lowered to a desired position in the well tubing.

A still further object is to provide a well tool, of the type described,wherein frangible means are provided for releasably holding the lockmandrel in the lower position.

Another object is to provide a well tool, of the type described, whereinthe tubular member is provided with a mechanically expansible sealingmeans and the lock mandrel is provided with an expander for moving thesealing means into sealing engagement with the well tubing when the lockmandrel is moved to the lower position.

Still another object is to provide a well tool, of the type described,wherein the lock mandrel is provided with an upwardly extending pumpseating nipple for receiving the hold down device of a pump assembly.

A still further object is to provide a well tool, of the type described,wherein the pump seating nipple prothe pump hold down device.

Additional objects and advantages of the invention will be readilyapparent from the reading of the following description of a deviceconstructed in accordance with the invention, and reference to theaccompanying drawings thereof, wherein:

Figure 1 is a vertical sectional view of the upper portion of a welltool embodying the invention being lowered in a well tubing by a runningtool suspended from a flexible line lowering mechanism.

Figure 1a is a view similar to Figure 1 and being a continuation thereofshowing the lower portion of the well tool; a

Figure 2 is a vertical sectional view of the upper portion of the welltool of Figure 1 showing it locked in position in the well tubing;

Figure 2a is a view similar to Figure 2 and being a continuation thereofshowing the lower portion of the well tool;

Figure 3 is a vertical sectional view of the upper portion of the welltool, similar to Figure 2, showing a pump hold down device positioned inthe pump seating nipple of the well tool;

Figure 3a is a view similar to Figure 3 and being a continuation thereofshowing the lower portion of the well tool; and

Figure 4 is a horizontal sectional view taken on line 44 of Figure 1a.

Referring now to the drawings, the well tool 10 includes a tubular outermember 11 having a plurality of integral dependent resilient colletfingers 12, preferably having a diametrically opposed pair of suchfingers. Each of the fingers is provided at its lower end with anexternal boss 13 having a substantially horizontal downwardly facinglower stop shoulder 14 and a downwardly and outwardly beveled upper camshoulder 15.

The resilient fingers are also provided with internal downwardly andinwardly extending camming surfaces 16 and stop shoulders 17 disposedbelow the camming surfaces which are engageable by the downwardly andin-' wardly inclined annular shoulder 18 at the lower enlarged endportion 19 of a lock mandrel 20 telescoped in the tubular member 11. Theresilient fingers are also provided with internal bosses 21, spacedabove the stop shoulders 17, and having upper inwardly and downwardlysloping shoulders 22 which are adapted to be engaged by the annularshoulder 18 of the ,lock mandrel when the latter is moved downwardlyfrom the upper inoperative position in the tubular member, shown inFigure 1a, and lower inwardly and upwardly sloping shoulders 23 whichare adapted to be engaged by the external upwardly facing annularshoulder 24 at the upper end of the enlarged portion 19 of the lockmandrel, when the lock mandrel is in the lower locking position, shownin Figure 2a.

The lower portions of the resilient fingers 12 are provided withvertical slots 26 through which extend latch retainer pins 27. Springlatches 28 each have one end wrapped or bent about a pin 27 whereby theyare pivotally mounted thereon. The spring latches 28 are formed withinternal hook or latch portions 29 which are adapted to engage the latchpin 27 of the opposite resilient finger whereby the resilient fingersmay be releasably held or latched thereby in the inner positions shownin Figure In. Each latch spring also has an outwardly extending straightcatch portion 30 which is inclined outwardly and upwardly of theresilient fingers when the spring latches are in operative position(Figure 1a) holding the resilient fingers in their inner positions.

The catch portions 3t) of the latch springs bend upwardly and inwardlyas they encounter obstructions in the well tubing during downwardmovement of the tool and are thus positively held in engagement with theresilient fingers to retain the same in inner retracted position.However, upon upward movement of the tool the ends of the catch portionsengage the wall of the tubing or in coupling recesses and swingdownwardly, disengaging the hool; portions from the pins 27 oftheopposite resilient fingers to release the fingers for movement to theexpanded or outer anchoring position shown in Figure 2a.

The lock mandrel 20 is also provided with a latch pin housing 32 inwhich is disposed a frangible latch pin 33 biased outwardly by a spring34. The latch pin is held in the retracted position shown in Figure Inby engagement with the upper internal wall 35 of the tubular member 11when the lock mandrel is in its upper position therein, and is movedoutwardly to the extended position shown in Figure 2:: when the lockmandrel is moved to its lower position. In this lower position the latchpin prevents upward movement of the lock mandrel by engaging thedownwardly facing annular shoulder 36 of the tubular member and thuslocks or latches the resilient fingers in expanded locking position.

The upper end of the tubular member is externally threaded to receive aninternally threaded retainer ring 38 to which is bonded a resilient cupor sleeve seal member 39 having a slightly outwardly flared upper endprovided with an annular internal flange 40. The seal member ispositively mechanically expanded outwardly into sealing engagement withthe well tubing 41 by an expander 42 threaded on the upper end of thelock mandrel and having a frusto-conical lower surface 43 whichtelescopes into the upper portion of the seal member when the lockmandrel is moved to the lower position shown in Figures 2a and 3a.

A pump seating nipple 45 is threaded on the upper reduced portion 46 ofthe expander 42. The pump seating nipple is provided with a plurality ofapertures 48 adjable line operating tools 53.

The nipple is formed with an internal annular flange 55 which provides adownwardly facing horizontal annular lower shoulder 56 and a downwardlyand inwardly sloping camming shoulder 57.

The nipple receives a pump assembly hold down device or mechanism 60which is secured to the lower end of a suitable pump (not shown) bymeans of the upper threaded end portion 61. The hold down deviceincludes a tubular body or mandrel 62 having an annular stop shoulder 63for engaging the upper end of the seating nipple 45 and a seal or packerassembly 64 for sealing between the mandrel and the seating nipple. Theseal assembly may include resilient seal members 65 of the chevron or Vtype held in place by and between an upper retaining ring 66 and a lowerretaining ring 67. A lock nut 68 is threaded on the lower reduced endportion 69 of the mandrel to abut the lower retaining ring and thus holdthe seal member in place on the mandrel, the upper retainer ring 66abutting a downwardly facing external annular shoulder 70 of themandrel.

A collet 72 is threaded on the lower end of the mandrel 62 and itsresilient dependent fingers 73 are provided with external bosses 74 eachhaving an upwardly and outwardly sloping upper shoulder 76. The lowershoulders 75 cam the collet fingers inwardly upon engaging the upper camshoulder 57 of the flange 55, when the hold down device moves downwardlyin the seating nipple, to enable the bosses 74 to move to the lowerposition shown in Figure 3 wherein their upper shoulders 76 engage thelower shoulder 56 of the flange 55 and thus lock or hold the hold downdevice 60 in place in the seating nipple against upward movement. Anintentional strong upward pull on the hold down device, however, as willbe explained hereinafter, will cause the upper shoulders 76 to cam thecollet fingers inwardly whereby the hold down device may be releasedfrom the landing nipple when desired. The resiliency of the fingerstherefore restrains the hold down mechanism in place in the seatingnipple.

The well tool 10 is used in oil wells whose tubing has not been providedwith pump seating nipples originally because the oil wells flowednaturally upon completion. When such wells cease to flow naturally, itis often necessary to install pumping equipment in the well tubing. Suchpumping equipment must be anchored within the tubing and sealed in placeto prevent leakage therebetween. The well tool is lowered into the welltubing 41, with all operative elements thereof in the positions shown inFigures 1 and la. The outer portions 30 of the spring latches 28 engagethe inner wall of the well tubing and, since they are resilient andextend angularly upwardly, flex upwardly upon meeting obstructions suchas the upper ends of the tubing sections 80 at eachcoupling recess 81formed at the couplings 82 which connect adjacent sections of the welltubing. The spring latch, of course, holds the lower ends of theresilient fingers 12 in the inner or retracted positions of Figure la toprevent engagement of the bosses 13 thereof with any obstructions of thewell tubing during downward movement of the well tool in the welltubing. The'seal member 39 'is also in retracted or non-expandedposition during such downward movement of the well tool.

When the well tool reaches the desired position in the well tubing thetool is moved upwardly, by means of the running tool, and the outer endsof the spring latches engage the lower end of a tubing section so thatcontinued upward movement of the well tool causes the latch springs topivot downwardly about the pins 27 of the resilient fingers 12 on whicheach is mounted and out of engagement with the pins of the oppositeresilient fingers, whereby the resilient fingers are freed to movetoward expanded positions. The bosses 13 then engage the inner wall ofthe well tubing and, as the well tool is moved upwardly, enter into thecoupling recess, whereupon a downward movement of the well tool causesthe downwardly facing stop shoulders 14 thereof to engage the upper endof thelower tubing section to prevent further downward movement of thewell tool.

Downward jars are then imparted to the running too] and thus to the lockmandrel. This jarring or downward force causes the lock mandrel to earnthe resilient fingers outwardly, by the action of the cam shoulders 18and 22 of the lock mandrel and of the resilient fingers, to permit thelower end of the lock mandrel to move past the in ternal bosses 21 ofthe resilient fingers.

Continued downward movement of the lock mandrel, caused by such jars,continues until the shoulder 18 of the lock mandrel engages the stopshoulders 17 of the fingers. In this lower position, the lock mandrelengages the inner surfaces of the fingers and holds them locked inexpanded position, wherein the bosses 13 thereof are disposed in thecoupling recess 81, anchoring the well tool in the well tubing againstmovement either upwardly or downwardly therein. I

The shoulders 23 and 24 of the lock fingers and of the lock mandrel arenow in engagement and tend to prevent accidental upward movement of thelock mandrel from its lower locking position. The latch pin 33 now alsoserves this function since it is in extended position below the shoulder36 of the tubular member 11.

Simultaneously with the downward movement of the lock mandrel, theexpander 42 moved into the seal member 39 and its lower frusto-conicalportion caused the uper end of the seal member to expand outwardly intoengagement with the well tubing to seal between the well tool and thewell tubing.

The shear pins 49 are of such strength that upward jars now imparted tothe running toolwill cause the pinsto.

shear to disconnect the running tool from the seating nipple 45, leavingthe lock mandrel in the lower position shown in Figure 2a. The pumpseating nipple is now anchored in place and is ready to receive the holddown device 60 of a pump, not shown.

The hold down device is connected to the lower end of the pump assemblyby means of its threaded upper end portion 61, and as the pump assemblyis lowered into the well tubing the collet fingers 73 enter into theseating nipple and are cammed inwardly by engagement of the shoulders 75of the collet fingers with the shoulder 57 of the flange 55 to enablethe bosses 74 of the collet fingers to move past the flange. The colletfingers then move resiliently outwardly whereupon the engagement of theshoulders 76 and 56 resists upward movement of the pump hold down devicefrom the seating nipple 45. The packing or seal members 65 now sealbetween the mandrel 62 of the hold down device 60 and the seating nipple45 of the well tool 10.

The pump, not shown, may then be placed into operation in the usualmanner to pump well fluid from below the well tool to the surfacethrough the well tool and the hold down device.

When it is desired to remove the pump assembly, it is merely pulledupwardly with suflicient force to cause the cam shoulders 76 to move thecollet fingers 73 inwardly of the internal flange of the seating nipple45, whereupon the pump hold down device 60 is freed from the seatingnipple for upward movement through the well tubing, the well tool beingleft in place, in the position shown in Figures 2 and 2a. The we l toolmay be again used to receive a pump hold down device if the removal ofthe pump assembly was merely temporary, as for repairs, or it may thenbe removed.

The well tool may be removed by the use of a suitable retrieving tool orspear (not shown) having a prong telescopable into the seating nipple 45provided with means for engaging the downwardly facing shoulder 56 ofthe internal flange S5 of the seating nipple 45. An upward pull or jarsimparted to the seating nipple cause the pin 33 to shear, whereby thelock mandrel is freed to move upwardly in the tubular mandrel. Furtherjars then cause the shoulders 24 and 23 of the bosses 21 and the lockmandrel, respectively, to cam the resilient fingers 12 outwardly topermit the lower enlarged portion of the lock mandrel to move upwardlypast the internal bosses 21 of the resilient fingers. Simultaneously,the expander 42 moves upwardly from the seal member 39 which then movesback to its retracted non-sealing position.

The engagement of the shoulders 24 and 36 of the lock mandrel and thetubular member then causes the tubular member to be moved upwardly withthe lock mandrel, the upper cam shoulders 15 of the bosses camming theresilient fingers inwardly upon encountering obstructions during theupward movement of the well tool to the surface.

It will thus be seen that a new and improved well tool has beenillustrated and described, which has a tubular member 11 provided withstop means 13 biased outwardly for limiting downward movement of thetool and latched by means 28 in retracted position. It will also be seenthat the tubular member is provided with a seal member at its upper endand that a hollow member 19 is mounted for longitudinal limited movementin the tubular member, the hollow member including a lock mandrel 20 forlocking the stop members in expanded or outer position, an expander 42for expanding the seal member 39 into sealing position, and a seatingnipple 45 for receiving a pump hold down device 60.

It will also be seen that the hollow member is provided with areleasable means, the shear pin 33, for holding the hollow member in itslower position relative to the tubular member whereby the seal memberand the stop members are positively held in their expanded or operativepo sitions. Likewise, it will be seen that the well tool 10 may beremoved from the well tubing by imparting upward jars to the hollowmember 19 which actuate the releasable means to free the hollow memberfor limited upward movement relative to the tubular member.

The foregoing description of the invention is explanatory only, andchanges in the details of the construction illustrated may be made bythose skilled in the art, within the scope of the appended claims,without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well tool including: an outer tubular member having a pair ofdiametrically opposed downwardly extending arms having their lower endsresiliently outwardly biased and each arm having on its lower endoutwardly projecting stop means for anchoring said tubular member in awell conductor'when in an outer position; pivotally mounted latch meanson the lower end of one of said arms engaging the other of said arms forreleasably securing said projecting stop means in retracted position;expansible seal means on said tubular member above said arms; and ahollow tube member slidable longitudinally in said outer tubular memberand having a lock means thereon engageable with the lower free endportion of said arms for locking said projecting stop means in saidouter position, an expander on said hollow tube member engageable withsaid seal means for expanding said seal means into sealing position whensaid hollow member is moved downwardly in said outer tubular member; andshoulder means in said hollow member engageable by a well devicetelescopable into said hollow tube member for holding said device insaid hollow tube member.

2. A well tool for use in a well conductor having an internal recessincluding: a tubular member having diametrically opposed downwardlyextending resilient arms having their lower ends outwardly biased andeach of said arms having on its lower end outwardly projecting stopmeans for entering into the recess in said well conductor to preventlongitudinal movement of the tubular member in the well conductor;hinged latch means on said lower end of one of said resilient armsengaging the opposite arm for holding said stop means in retractedposition to permit the tubular member to be lowered in the wellconductor, said latch means having a portion extending upwardly andoutwardly therefrom and engageable with a downwardly facing obstructionin the well conductor upon upward movement of the tubular member in thewell conductor to move said latch means downwardly out of engagementwith said opposite arm to release said stop means from said retractedposition; expansible seal means carried by said tubular member abovesaid arms for sealing between the well conductor and the tubular member;and a hollow tube member longitudinally movable in said tubular member,said hollow tube member having a lock means thereon engageable with thelower free end portion of said resilient depending arms for locking saidstop means against inward movement toward said retracted position whensaid hollow tube member is in a lower position in the tubular member,means on said hollow tube member movable therewith into engagement withsaid seal means for expanding said seal meanswhen said hollow tubemember is in said lower position, and shoulder means on said hollow tubemember engageable by a well device telescopable into said hollow tubemember for holding said device in said hollow member.

3. A well tool for use in a well conductor having an internal recessincluding: a tubular member having diametrically opposed downwardlyextending resilient arms having their lower ends outwardly biased andeach of said arms having on its lower end outwardly projecting stopmeans for entering into the recess in said well conductor to preventlongitudinal movement of the tubular member in the well conductor;hinged latch means on said lower end of one of said resilient armsengaging the opposite arm for holding said stop means in retractedposition to permit the tubular member to be lowered in the wellconductor, said latch means having a portion extending upwardly andoutwardly therefrom and engageable with a downwardly facing obstructionin the well conductor upon upward movement of the tubular member in thewell conductor to move said latch means downwardly out of engagementwith said opposite arm to release said stop means from said retractedposition; expansible seal means carried by said tubular member abovesaid arms for sealing between the well conductor and the tubular member;a hollow tube member longitudinally movable in said tubular member, saidhollow tube member having a lock means thereon engageable with the lowerfree end portion of said resilient depending arms for locking said stopmeans against inward movement toward said retracted position when saidhollow tube member is in a lower position in the tubular member, meanson said hollow tube member movable therewith into engagement with saidseal means for expanding said seal means when said hollow tube member isin said lower position, and shoulder means on said hollow tube memberengageahle by a well device telescopable into said hollow tube memberfor holding said device in said hollow tube member; and cooperatingoppositely facing shoulder means on said hollow tube member and on saidtubular member for releasably holding said hollow tube member in saidlower position in said tubular member.

4. A well tool for use in a well conductor having an internal recessincluding: a tubular member having a pair of diametrically opposeddownwardly extending re silient arms having their lower ends outwardlybiased and each of said arms having on its lower end outwardlyprojecting stop means for entering into the recess in said wellconductor to prevent longitudinal movement of the tubular member in thewell conductor; hinged latch means on said lower end of one of saidresilient arms engaging the opposite arm for holding said step means inretracted position to permit the tubular member to be lowered in thewell conductor, said latch means having a portion extending upwardly andoutwardly therefrom and engageable with a downwardly facing obstructionin the well conductor upon upward movement of the tubular member in thewell conductor to move said latch means downwardly out of engagementwith said opposite arm to release said stop means from said retractedposition; expansible seal means carried by said tubular member abovesaid arms for sealing between the well conductor and the tubular member;an elongate tubular mandrel longitudinally movable in said tubularmember, said mandrel having a lock means for locking said stop meansagainst inward movement toward said retracted position when said mandrelis in a lower position in the tubular member, means on said mandrelmovable therewith into engagement with said seal means for expandingsaid seal means when said mandrel is in said lower position, andshoulder means on said mandrel engageable by a well device telescopableinto said mandrel for holding said device in said mandrel; and means onsaid resilient arms engageable with the lower end of said mandrel forlimiting downward movement of said mandrel in said tubular member.

5. A well tool for use in a well conductor having an internal recessincluding: a tubular member having a pair of diametrically opposeddownwardly extending resilient arms having their lower ends outwardlybiased, each of said arms having on its lower end outwardly projectingstop means for entering into the recess in said well conductor toprevent longitudinal movement of the tubular member in the wellconductor; latch means hingedly connected on the lower end of one ofsaid resilient arms and swingable to position engaging the oppo site armfor holding said stop means in retracted position to permit the tubularmember to be lowered in the well conductor, said latch means having aportion extending upwardly and outwardly therefrom and engageable with adownwardly facing obstruction in the well conductor upon upward movementof the tubular member in the well conductor to move said latch meansdownwardly out of engagement with said opposite arm to release said stopmeans from said retracted position; expansible seal means carried bysaid tubular member above said arms for sealing between the wellconductor and the tubular member; an elongate tubular mandrellongitudinally movable in said' tubular member, said mandrel having alock means thereon engageable with the lower free end portion'or" saidresilient depending arms for locking said stop means against inwardmovement toward said retracted position when said mandrel is' in a lowerposition in the tubular member, means on said mandrel movable therewithinto engagement with said seal means for expanding said seal means whensaid mandrel is in said lower position, and shoulder means on saidmandrel engageable by a well device telescopable into said mandrel forholding said device in said mandrel; means on said resilient armsengageable with the lower end of said mandrel for limiting downwardmovement of said mandrel in said tubular member; and cooperatingoppositely facing shoulder means on said mandrel and on said tubularmember for releasably holding said mandrel in said lower position.

6, A well tool for use in a well conductor having an internal recessincluding: a tubular member having a pair of diametrically opposeddownwardly extending resilient arms having their lower ends outwardlybiased, each of said arms having on its lower end outwardly projectingstop means for entering into the recess in said well conductor toprevent longitudinal movement of the tubular member in the wellconductor; latch means hingedly connected on the lower end of one ofsaid resilient arms and swingable to position engaging the opposite armfor holding said stop means in retracted position to permit the tubularmember to be lowered in the well conductor, said latch means having aportion extending upwardly and outwardly therefrom and engageable with adownwardly facing obstruction in the well conductor upon upward movementof the tubular member in the well conductor to move said latch meansdownwardly out of engagement with said opposite arm to release said stopmeans from said retracted position; expansible seal means carried bysaid tubular member above said arms for sealing between the wellconductor and the tubular member; and an elongate tubular mandrellongitudinally movable in said tubular member, said mandrel having alock means thereon engageable with the lower free end portion of saidresilient depending arms for locking said stop means against inwardmovement toward said retracted position when said mandrel is in a lowerposition in the tubular member, means on said mandrel movable therewithinto engagement with said seal means for expanding said seal means whensaid mandrel is in said lower position, and shoulder means on saidmandrel engageable by a well device telescopable into said mandrel forholding said device in said mandrel, said mandrel providing an internalsurface for engagement by a sealing means of the device to prevent fiuidflow therebetween.

7. A well tool including: a tubular member having a plurality ofresilient integral dependent finger members spaced circumferentially ofthe lower end of said tubular member, each of said dependent membershaving laterally outwardly extending bosses near their lower ends; saidbosses haying outwardly and downwardly sloping upper camming surfacesand outwardly extending lower stop surfaces; latch means hingedlysecured to the lower end of one of said finger members and swingableinto engagement with the other of said finger members for releasablyholding said dependent finger members in inwardly retracted position,said latch means having trip means extending outwardly and upwardly fromits point of engagement with said other dependent finger memberssufiiciently to engage the bore wall of a well conductor in which thewell tool is inserted to move said latch means out of engagement withsaid other depending finger members on said tubular member to releasethe dependent finger members from said retracted position; an outwardlyexpansible seal carried on the upper end of said tubular member; and anelongate tubular mandrel slidably mounted in said tubular member forlimited longitudinal movement beween upper and lower positions in saidtubular member; said mandrel having an enlarged lower end portionengageable wtih the lower end portions of said dependent finger memberswhen said mandrel is in said lower position to prevent inward movementof said dependent finger members toward said retracted position, saidmandrel having a wedge expander means movable downwardly into said sealmeans for expanding said seal means when said mandrel is moved from saidupper position to said lower position.

8. A well tool including: a tubular member having a plurality ofresilient integral dependent finger members spaced circumferentially ofthe lower end of said tubular member, each of said dependent membershaving laterally outwardly extending bosses near their lower ends; latchmeans hingedly secured to the lower end of one of said finger membersand swingable into engagement with the other end of said finger membersfor releasably holding said dependent finger members in inwardlyretracted position, said latch means having trip means extendingoutwardly and upwardly from its point of engagement with said otherdependent finger members sufficiently to engage the bore wall of a wellconductor in which the well tool is inserted to move said latch meansout of engagement with said other depending finger members on saidtubular member to release the dependent finger members from saidretracted position, said bosses having downwardly and outwardly slopingupper camming surfaces and outwardly extending lower stop surfaces; anoutwardly expansible seal carried on the upper end of said tubularmember; an elongate tubular mandrel slidably mounted in said tubularmember for limited longitudinal movement between upper and lowerpositions in said tubular member; said mandrel having an enlarged lowerend portion engageable with the lower end portions of said dependentfinger members when said mandrel is in said lower position to preventinward movement of said dependent finger members toward said retractedposition, said mandrel having a wedge expander means movable downwardlyinto said seal means for expanding said seal means when said mandrel ismoved from said upper position to said lower position; and cooperatingoppositely facing shoulders on each said mandrel and said dependentfinger memebrs for releasably holding said mandrel in said lowerposition in said tubular member.

9. A well tool including: a tubular member having a plurality ofresilient integral dependent finger members spaced circumferentially ofthe lower end of said tubular member, each of said dependent membershaving laterally outwardly extending bosses near their lower ends; latchmeans hingedly secured to the lower end of one of said finger membersand swingable into engagement with the other end of said finger membersfor releasably holding said dependent finger members in inwardlyretracted position, said latch means having trip means extendingoutwardly and upwardly from its point of engagement with said otherdependent finger members sufiiciently to engage the bore wall of a wellconductor in which the well tool is inserted to move said latch meansout of engagement with said other depending finger members on saidtubular member to release the dependent finger members from saidretracted position, said bosses having downwardly and outwardly slopingupper camming surfaces and outwardly extending lower stop surfaces; anoutwardly expansible seal carried on the upper end of said tubularmember; and an elongate tubular mandrel slidably mounted in said tubularmember for limited longitudinal movement between upper and lowerpositions in said tubular member; said mandrel having an enlarged lowerend portion engageable with the lower end portions ofsaid dependentfinger members when said mandrel is in said lower position to preventinward movement of said dependent finger members toward said retractedposition, said mandrel having a wedge expander means movable downwardlyinto said seal means for expanding said seal means when said mandrel ismoved from said upper position to said lower position, mandrel havingits upper end open and adapted to receive a well device; and internaldownwardly facing shoulder means in said mandrel disposed for engagingthe well device to hold it against upward displacement in the hollowmember.

10. A Well tool including: a tubular member having a pair ofdiametrically opposed downwardly extending resilient arms, each of saidarms having laterally outwardly extending bosses on their lower ends;latch means hingedly secured to the lower end of one of said fingermembers and swingable into engagement with the other end of said fingermembers for releasably holding said finger members in inwardly retractedposition, said latch means having trip means extending outwardly andupwardly from its point of engagement with said other dependent fingermembers sufiiciently to engage the bore wall of a well conductor inwhich the well tool is inserted to move said latch means out ofengagement with said other depending finger members on said tubularmember to release the finger members from said retracted position, saidbosses having downwardly and outwardly sloping upper camming surfacesand outwardly extending lower stop surfaces; an outwardly expansibleseal carried on the upper end of said tubular member; and an elongatetubular mandrel having a lower end portion telescoped in said tubularmember, said mandrel being slidably mounted on said tubular member forlimited longitudinal movement between an upper position and a lowerposition; upwardly facing shoulder means on said finger members forengaging the lower end of said mandrel to hold said mandrel in saidupper position when said finger members are in said retracted position,said mandrel being disposed between the lower end portions of saidfinger members when in said lower position to prevent inward movementthereof toward said retracted position, said mandrel having an enlargedexpander member thereon movable downwardly therewith into said sealmeans for expanding said seal means upon movement of said mandrel fromsaid upper to said lower position.

11. A well tool including: a tubular member having apair ofdiametrically opposed downwardly extending resilient arms, each of saidarms having laterally outwardly extending bosses near their lower ends;said bosses having outwardly and downwardly sloping upper cammingsurfaces and outwardly extending lower stop surfaces; latch meanshingedly secured to the lower end of one of said finger members andswingable into engagement with the other of said finger members forreleasably holding said finger members in inwardly retracted position,said latch means having trip means extending outwardly and upwardly fromits point of engagement with said other dependent finger memberssufiiciently to engage the bore wall of a well conductor in which thewell tool is inserted to move said latch means out of engagement withsaid other depending finger members on said tubular member to releasethe finger members from said retracted position; an outwardly expansibleseal carried on the upper end of said tubular member; an elongatetubular mandrel having a lower end portion telescoped in said tubularmember, said mandrel being slidably mounted on said tubular member forlimited longitudinal movement between an upper position and a lowerposition; upwardly facing shoulder means on said finger members forengaging the lower end of said mandrel to hold said mandrel in saidupper position when said finger members are in said retracted position,said mandrel extending between the lower end portions of said fingermembers when in said lower position to prevent inner movement thereoftoward said retracted position, said mandrel having an enlarged expandermember thereon movable downwardly therewith into said seal means forexpanding said seal means upon movement of said mandrel from said upperto said lower position, and cooperating oppositely facing shoulders oneach said mandrel and said finger members engageable for releasablyholding said mandrel in said lower position.

12. A well tool including: a tubular member having a pair ofdiametrically opposed downwardly extending resilient arms, each of saidarms having laterally outwardly extending bosses near their lower ends;said bosses having outwardly and downwardly sloping upper cammingsurfaces and outwardly extending lower stop surfaces; latch meanshingedly secured to the lower end of one of said finger members andswingable into engagement with the other of said finger members forreleasably holding said finger members in inwardly retracted position,said latch means having trip means extending outwardly and upwardly fromits point of engagement with said other dependent finger memberssufficiently to en gage the bore wall of a well conductor in which thewell tool is inserted to move said latch means out of engagement withsaid other depending finger members on said tubular member to releasethe finger members from said retracted position; an outwardly expansibleseal carried on the upper end of said tubular member; an elongatetubular mandrel having a lower end portion telescoped in said tubularmember, said mandrel being slidably mounted on said tubular member forlimited longitudinal movement between an upper position and a lowerposition; upwardly facing shoulder means on said finger members forengaging the lower end of said mandrel to hold said mandrel in saidupper position when said finger members are in said retracted position,said mandrel extending between the lower end portions of said fingermembers when in said lower position to prevent inward movement thereoftoward said retractedposition, said mandrel having an enlarged expandermember thereon movable downwardly therewith into said seal means forexpanding said seal means upon movement of said' mandrel from said upperto said lower position; and cooperating oppositely facing shoulders oneach said mandrel and said finger members engageable for releasablyholding said mandrel in said lower position, said mandrel having anupper portion extending above said tubular member open at its upper endfor telescopi cally receiving a well device.

13. A well tool including: a tubular member having a pair ofdiametrically opposed downwardly extending resilient arms, each of saidarms having laterally outwardly extending bosses near their lower ends;said bosses having outwardly and downwardly sloping upper cammingsurfaces and outwardly extending lower stop surfaces; latch meanshingedly secured to the lower end of one of said finger members andswingable into engagement with the other of said finger members forreleasably holding said finger members in inwardly retracted position,said latch means having trip means extending outwardly and upwardly fromits point of engagement. with said other dependent finger memberssufiiciently to engage the bore wall of a well conductor in which thewell tool is inserted to move said latch means out of engagement withsaid other depending finger members on said tubular member to releasethe finger members from said retracted position; an outwardly expansibleseal carried on the upper end of said tubular member; an elongatetubular mandrel having a lower end portion telescoped in said tubularmember, said mandrel being slidably mounted on said tubular member forlimited longitudinal movement between an upper position and a lowerposition; upwardly facing shoulder means on said finger members forengaging the lower end of said mandrel to hold said mandrel in saidupper position when said finger members are in said retracted position,said mandrel extending between the lower end portions of said fingermembers when in said lower position to prevent inward movement thereoftoward said retracted position, said mandrel having an enlarged expandermember thereon movable downwardly therewith into said seal means forexpanding said seal means upon movement of said mandrel from said upperto said lower position, and cooperating oppositely facing shoulders oneach said mandrel and said finger members engageable for releasablyholding said mandrel in said lower position, said mandrel having anupper portion extending above said tubular member open at its upper endfor telescopically receiving a well device, said upper portion having aninternal surface engageable by a seal means of the well device.

14. A well tool including: a tubular member having a pair ofdiametrically opposed downwardly extending resilient arms, each of saidarms having laterally outwardly extending bosses near their lower ends;said bosses having outwardly and downwardly sloping upper surfaces;latch means hingedly secured to the lower end of one of said fingermembers and swingable into engagement with the other of said fingermembers for releasably holding said finger members in inwardly retractedposition, said latch means having trip means extending outwardly andupwardly from its point of engagement with said other dependent fingermembers sufliciently to engage the bore wall of a well conductor inwhich the well-tool is inserted to move said latch means out ofengagement with said other depending finger members on said tubularmember to release the finger members from said retracted position; anoutwardly expansible seal carried on the upper end of said tubularmember; an elongate tubular mandrel having a lower end portiontelescoped in said tubular member, said mandrel being slidably mountedon said tubular member for limited longitudinal movement between anupper position and a lower position; upwardly facing shoulder means onsaid finger members for engaging the lower end of said mandrel to holdsaid mandrel in said upper position when said finger members are in saidretracted position, said mandrel extending between the lower endportions of said finger members when in said lower position to preventinward movement thereof toward said retracted position, said mandrelhaving an enlarged expander member thereon movable downwardly therewithinto said seal means for expanding said seal means upon movement of saidmandrel from said upper to said lower position, and cooperatingoppositely facing shoulders on each said mandrel and said finger membersengageable for releasably holding said mandrel in said lower position,said mandrel having an upper portion extending above said tubular memberopen at its upper end for telescopically receiving a well device, saidupper portion having an internal surface engageable by a seal means ofthe well device, and a downwardly facing lock shoulder in the bore ofsaid mandrel disposed to be engaged by the well device to retain it insaid upper portion.

References Cited in the file of this patent UNITED STATES PATENTS2,028,418 Smith et al. Ian. 21, 1936 2,644,527 Baker July 7, 19532,669,305 Condra Feb. 16, 1954 2,671,512 Regan et al. Mar. 9, 1954UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION John wail, Jr etal,

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction and "shat the saidLetiers Patent should read as corrected belowo Column l2, line 29 claim14, for surfaces latch read camming surfaces and outwardly extendinglower stop surfaces; latcho Signed and sealed izhis 5th day of July19609 (SEAL) Atfiest:

' KARL H0 AXLINE 7 ROBERT C. WATSON Attesting Officer Conmissioner ofPatents

